The lipid fraction of human semen has been separated by
LH 20 Sephadex chromatography and TLC and the resulting
fractions analysed by GCMS. Evidence is presented for the
existence in semen of several prostaglandins, including
19 -OH PG F₁α, 19-OH PG F₂α, 8-iso 19-OH PG El, 8 -iso 19-OH
PG E₂, 8 -iso PG F10, 8 -iso PG F20 , 8 -iso PG E₁ and 8-iso
PG E₂. None of these compounds have previously been described
in semen, and the first five have not been described from
any source. Evidence is also presented for the existence
of a group of prostaglandins isomeric with the dinor prostaglandins
El₁, E₂, F₁α and F₂α.
A method for the preparation of crystalline 19-OH PG
E₁ from macaque semen is described. Evidence is presented
for the existence of a pair of dihydroxy E prostaglandins,
tentatively identified as 18,19 dihydroxy PG E₁ and an isomeric
compound in the semen of the stump-tailed macaque.
The effects of 19-OH PG E₁ on non-pregnant and pregnant
human isolated myometrial strips have been studied. 19-OH
PG E₁, like PG E₁, was found to relax non-pregnant strips,
the equipotent molar ratio being E₁:19-OH E₁ = 1:4.
19-OH PG E₁ was also found to relax pregnant strips, unlike
PG E₁, and a significant effect was demonstrated at 50 ng /ml.
Examination of homogenates of the seminal vesicle of
the stump tailed macaque by GCMS showed them to contain
large amounts of 19-OH E prostaglandins, and these levels
increased on incubation, an effect which was inhibited by
indomethacin. Incubation of homogenates with radioactively-labelled
eicosa-8,11,14-trienoic acid, arachidonic acid, PG E₁, PG E₂, PG F₂α or
PG F₃α produced no significant incorporation of radioactivity into the 19-hydroxy
prostaglandin fractions. It is concluded that the biosynthesis
of 19-OH PGs takes place via a separate pathway from that
leading to the classical prostaglandins.
Some observations on dynamic aspects of seminal prostaglandin
production in man are presented, along with the
results of a study on the species distribution of the
19-hydroxy E prostaglandins
